Thirds set of IIO fixes for the 4.11 cycle. * core - iio sw-device - ensure configfs is enabled both when building as module and built in. * ak8974 - drop incorrect __exit markup on remove. * hid-sensor-trigger - code reorganise to avoid losing settings if a power cycle occurs during S3. * lsm6dsx - fix incorrect overwrite of parts of FIFO_CTRL2 register during watermark configuration. * ti-am335x - fix a hard to hit bug when reenabling from a fifo overrun by waiting for current cycle to finish.